EN 10204 3.1 certificate: what to check

Short answer: EN 10204 3.1 is an inspection certificate for metal products that shows the actual test results of that specific batch: chemical composition and mechanical properties. The certificate is validated by the manufacturer's authorised inspection representative, who is independent of the manufacturing department. Thanks to the heat number, every tube, sheet or bar can be traced back to the steel melt.

What is EN 10204?

EN 10204 is the European standard that defines the types of inspection documents used when metal products are delivered. The standard does not tell you which steel grade or size to use, but how much evidence you get about the delivered material and who validates it. The current version is EN 10204:2004.

Certificate types: 2.1, 2.2, 3.1 and 3.2

In industry, the food industry and pressure systems, 3.1 is the usual minimum. Type 3.2 is ordered when the project requires third-party inspection.

What to check on a 3.1 certificate

• Manufacturer's name and certificate number.

• Product description and dimensions (e.g. tube 42.4 x 2.0 mm).

• Material and standard (e.g. EN 1.4301 / AISI 304, EN 10217-7 or EN 10088-2).

• Heat number, which must match the number marked on the product.

• Chemical composition (C, Cr, Ni, Mo etc.).

• Mechanical properties: yield strength Rp0.2, tensile strength Rm, elongation A.

• Reference to type EN 10204 3.1 and the inspector's signature or stamp.

If the heat number on the product and on the certificate do not match, the certificate does not prove that material.

When is a 3.1 certificate required?

• Pressure systems and process piping where the project or client requires material traceability.

• Food, pharmaceutical and chemical industries where the quality system requires proof of material origin.

• Construction projects where the client wants railings, structures or facade elements made of verified material.

If a project simply says "material with certificate", always ask whether type 3.1 or 3.2 is meant.

Material certificates from Kominox

Kominox supplies stainless steel grades 304, 316L and 430 as well as aluminium. Material certificates are available on request. State in your enquiry which certificate type the project requires, for example EN 10204 3.1.

See also: Stainless steel 304, Stainless steel 316L, Process pipes and Request a quote.

Frequently asked questions

What is the difference between a 3.1 and a 3.2 certificate?

Both contain the actual test results of the batch. A 3.1 is validated by the manufacturer's independent inspector; a 3.2 is additionally validated by the purchaser's representative or an official third party.

Is a 2.2 test report enough?

A 2.2 shows the manufacturer's general results, not those of this batch. If you need material traceability, ask for 3.1.

Is a 3.1 certificate the same as a "mill certificate"?

In everyday use, yes: mill test certificate, MTC and mill certificate usually mean an EN 10204 3.1 certificate. Check the type number on the document.

Can I get a material certificate from Kominox?

Yes, material certificates are available on request. State the required certificate type in your enquiry, for example EN 10204 3.1.